# what two numbers multiply together to equal 16 and add together to equal 15?

You can multiply two matrices if, and only if, the number of columns in the first matrix equals the number of rows in the second matrix. Otherwise, the product of two matrices is undefined. The product matrix's dimensions are $$\rightarrow$$ (rows of first matrix) × (columns of the second matrix ) In the picture on the left, the matrices can be multiplied since the number of columns in  the 1st one, matrix A, equals the number of rows in the 2nd, matrix B.... read more